When routing a connection through a network, there are well-known techniques for finding a least-cost-route or path. However, there are applications where the cost of a route is not the only factor. For example, some computer and network applications are delay sensitive and require finding a route that does not exceed a latency constraint for the entire route.
Another example occurs during the routing of circuits through an optical network. As an optical signal traverses an optical network, noise accumulates at each link. In practice, this noise can build up to a point at which the signal is not usable. When routing a circuit through an optical network, it may be necessary to select a route that meets signal-to-noise requirements or constraints.
Some techniques for finding a path through a network implement the Dijkstra algorithm. The Dijkstra algorithm is widely known as an algorithm to compute a least-cost-route efficiently. While these techniques will find a least-cost-route, they do not take into account constraints for end-to-end path accumulated metrics, such as latency and signal-to-noise constraints.